1,182 research outputs found

    Design description of the Tangaye Village photovoltaic power system

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    The engineering design of a stand alone photovoltaic (PV) powered grain mill and water pump for the village of Tangaye, Upper Volta is described. The socioeconomic effects of reducing the time required by women in rural areas for drawing water and grinding grain were studied. The suitability of photovoltaic technology for use in rural areas by people of limited technical training was demonstrated. The PV system consists of a 1.8-kW (peak) solar cell array, 540 ampere hours of battery storage, instrumentation, automatic controls, and a data collection and storage system. The PV system is situated near an improved village well and supplies d.c. power to a grain mill and a water pump. The array is located in a fenced area and the mill, battery, instruments, controls, and data system are in a mill building. A water storage tank is located near the well. The system employs automatic controls which provide battery charge regulation and system over and under voltage protection. This report includes descriptions of the engineering design of the system and of the load that it serves; a discussion of PV array and battery sizing methodology; descriptions of the mechanical and electrical designs including the array, battery, controls, and instrumentation; and a discussion of the safety features. The system became operational on March 1, 1979

    Operational performance of the photovoltaic-powered grain mill and water pump at Tangaye, Upper Volta

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    The first two years of operation of a stand alone photovoltaic (PV) power system for the village of Tangaye, Upper Volta in West Africa are described. The purpose of the experiment was to demonstrate that PV systems could provide reliable electrical power for multiple use applications in remote areas where local technical expertise is limited. The 1.8 kW (peak) power system supplies 120-V (d.c.) electrical power to operate a grain mill, a water pump, and mill building lights for the village. The system was initially sized to pump a part of the village water requirements from an existing improved well, and to meet a portion of the village grain grinding requirements. The data, observations, experiences, and conclusions developed during the first two years of operation are discussed. Reports of tests of the mills used in the project are included

    Tunisia Renewable Energy Project systems description report

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    In 1979, the Agency for International Development (AID) initiated a renewable energy project with the Government of Tunisia to develop an institutional capability to plan and institute renewable energy technologies in a rural area. The specific objective of the district energy applications subproject was to demonstrate solar and wind energy systems in a rural village setting. The NASA Lewis Research Center was asked by the AID Near East Bureau to manage and implement this subproject. This report describes the project and gives detailed desciptions of the various systems

    Potential Effects of Industrial Air Pollution and Wood-Product Supply and Demand, and Structure of the Wood-Products Industry, in Poland

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    This study aimed to determine potential changes in the production structure of the wood-processing industry up to 2020, resulting from unfavorable impact of industrial pollutants upon forests in Poland. The paper consists of four chapters. In the first section, forecasts of consumer demand for forest products, based on patterns of actual demand, are presented. The structure of industrial demand for wood assortments, and the degree to which it is met, are the topics of the second chapter. In the third chapter, we present forecasts of the possibilities of wood-raw-material consumption by industry with regard to the unfavorable impact of industrial pollution. The last chapter contains forecasts of production regarding foreseen changes in the structure of the wood-processing industry, taking into account qualitative changes in wood raw-material and expected changes in techniques and technology. Our results show that, up to 2020, negative effects of industrial pollutants on forests will have a significant influence on the degree of meeting consumer demands for wood products

    Mobilization of human hematopoietic stem/progenitor-enriched CD34+ cells into peripheral blood during stress related to ischemic stroke.

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    The bone marrow-derived stem/progenitor cells were demonstrated to play an important role in a regeneration of damaged tissue. Based on these observations we asked whether the stroke-related stress triggers mobilization of stem/progenitor cells from the bone marrow into the peripheral blood, which subsequently could contribute to regeneration of damaged organs. To address this issue, the peripheral blood samples were harvested from patients with ischemic stroke during the first 24 hrs as well as after the 48 (2nd day) and 144 hrs (6th day) since the manifestation of symptoms. In these patients we evaluated the percentage of hematopoietic stem/progenitor-enriched CD34+ cells by employing flow cytometry and the number of hematopoietic progenitor cells for the granulocyto-monocytic (CFU-GM) and erythroid (BFU-E)-lineages circulating in peripheral blood. We concluded that stress related to ischemic stroke triggers the mobilization of hematopoietic stem/progenitor cells from the bone marrow into peripheral blood. These circulating stem/progenitor cells may play an important role in the process of regeneration of the ischemic tissue

    Influence of hydrological conditions on the Escherichia coli population structure in the water of a creek on a rural watershed.

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    International audienceBACKGROUND: Escherichia coli is a commensal bacterium of the gastro-intestinal tract of human and vertebrate animals, although the aquatic environment could be a secondary habitat. The aim of this study was to investigate the effect of hydrological conditions on the structure of the E. coli population in the water of a creek on a small rural watershed in France composed of pasture and with human occupation. RESULTS: It became apparent, after studying the distribution in the four main E. coli phylo-groups (A, B1, B2, D), the presence of the hly (hemolysin) gene and the antibiotic resistance pattern, that the E. coli population structure was modified not only by the hydrological conditions (dry versus wet periods, rainfall events), but also by how the watershed was used (presence or absence of cattle). Isolates of the B1 phylo-group devoid of hly and sensitive to antibiotics were particularly abundant during the dry period. During the wet period and the rainfall events, contamination from human sources was predominantly characterized by strains of the A phylo-group, whereas contamination by cattle mainly involved B1 phylo-group strains resistant to antibiotics and exhibiting hly. As E. coli B1 was the main phylo-group isolated in water, the diversity of 112 E. coli B1 isolates was further investigated by studying uidA alleles (beta-D-glucuronidase), the presence of hly, the O-type, and antibiotic resistance. Among the forty epidemiolgical types (ETs) identified, five E. coli B1 ETs were more abundant in slightly contaminated water. CONCLUSIONS: The structure of an E. coli population in water is not stable, but depends on the hydrological conditions and on current use of the land on the watershed. In our study it was the ratio of A to B1 phylo-groups that changed. However, a set of B1 phylo-group isolates seems to be persistent in water, strengthening the hypothesis that they may correspond to specifically adapted strains
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